Highly tensile and sensitive strain sensors with micro–nano topology optimization

With the extensive application of flexible sensors in various wearable electronics being continuously explored, researchers are paying more and more attention to improving their sensitivity while ensuring high stretchability. In this study, a novel fiber strain sensor was proposed with micro–nano topology optimization, which was achieved through a simple, cost-effective and scalable method. A TPU/PEO substrate was prepared by electrospinning technology, then the fibrous membrane was immersed in deionized water to wash away the PEO and obtain the micro–nano topological structure. Carbon nanotubes (CNTs) and graphene were further adsorbed on the etched TPU fibrous membrane through ultrasonic treatment to obtain TPU:PEO/CNTs and TPU:PEO/graphene sensors, respectively. Both experimental and simulation results showed that the optimization of the PEO ratio is crucial for the balance between wide deformation and high sensitivity. A wide detection range (0–650%) and high sensitivity (GFmax = 976.89) were obtained for the TPU:PEO/graphene sensor, demonstrating its suitability for high-performance strain sensors. It can not only capture minor human movements, but also be effectively applied in fitness scenarios, which may contribute to personalized scientific training and reduce sports injuries.